1. Field of the Invention
The present invention relates to an electrode layer for capacitors, a method of manufacturing the electrode layer, a unit sensor using the electrode layer, and a tactile sensor using the unit sensor. More particularly, the present invention relates to an electrode layer for flexible capacitors that can be manufactured using a flexible substrate and that can be extended, a method of manufacturing the electrode layer, a unit sensor using the electrode layer, and a tactile sensor using the unit sensor.
2. Description of the Related Art
Much research has been carried out into application of tactile sensors to robots. However, the research has failed to realize the commercial results until a recent date. With recent appearance of human robots, the research has increasingly focused on the human robots. For example, robots that can be utilized in real lives of humans, such as a cleaning robot named “Roomba,” have been placed on the market. Consequently, the robots will have an influence on many parts of human life in addition to special purposes, such as factories. It is required that the robots have a tactile sensation to interact with humans. As a result, the necessity of tactile sensors for robots is being increased. The tactile sensors must be as flexible and soft as human skin. Furthermore, the tactile sensors and the systems in the tactile sensors must be protected from external impacts. In addition, the tactile sensors must be freely located over desired areas.
Most tactile sensors developed for robots are made of flexible polyimide-based plastic, rubber, or cloth. Also, the tactile sensors have a thin plate-shaped two-dimensional array structure. A Pressure sensor is a sensor whose resistance or capacitance is changed by pressure. A typical example of a pressure sensor is disclosed in U.S. Pat. No. 6,826,968. However, the developed tactile sensors have problems in that high resolution of below 1 mm, which is similar to human skin, cannot be realized due to the restrictions of a manufacturing process, and that interference between neighboring unit sensors is great, and the tactile sensors cannot be freely located over desired areas due to structural restrictions.